i have this code for the user-edit.php what i need with this code is to fetch user data from database and show it to the textbox and also the user able to edit the textbox value and updating the database

<?php
    include("config/session.php");
    include("config/connection.php");
    $user_id =  $_SESSION['LOGGED_USER_ID']; 
?>

<?php 
    $sql_query = "SELECT * FROM table_users WHERE `SNo` = '$user_id'"; 
    $query = mysql_query($sql_query);
    //$i = 1;
    $fetch = mysql_fetch_assoc($query);

    //$user_id = $_GET['id'];   

?>      
<form name="form1" action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST" >
    <fieldset>

        <p>
            <label for="simple-input" >User Name</label>
            <input type="text" id="UserName" class="round default-width-input" autofocus name="UserName" value="<?php echo $fetch['UserName'];?>" readonly="readonly" />
        </p>
        <p>
            <label for="simple-input" >Password</label>
            <input type="text" id="pass_word" class="round default-width-input" autofocus name="pass_word" value="<?php echo $fetch['pass_word'];?>" />
        </p>
        <p>
            <label for="simple-input" >Email ID</label>
            <input type="text" id="Email" class="round default-width-input" autofocus name="Email" value="<?php echo $fetch['Email'];?>" />

        </p>
        <p>
            <label for="simple-input" >Website</label>
            <input type="text" id="website" class="round default-width-input" autofocus name="website" value="<?php echo $fetch['website'];?>" />
        </p>


    </fieldset>

    <input type="submit" class="btn btn-primary btn-large" name="form_submit" value="Update Data"/> 

</form>

<?php

if(isset($_POST['form_submit']))
{
    "UPDATE `table_users` SET `pass_word` =  '".$_POST['pass_word']."',`Email` =  '".$_POST['Email']."',`website` =  '".$_POST['website']."', WHERE `SNo` = '$user_id'";

    // sql query for update data into database
    if(mysql_query($sql_query))
     {

      echo '<script type="text/javascript">';
      echo 'alert("Data Are Updated Successfully");';
      echo '</script>';

     }
     else
     {

      echo '<script type="text/javascript">';
      echo 'alert("error occured while updating data");';
      echo '</script>';
    }
    }
?>

        </div>
    </div>                          
</div>

been working with this for hours and still the data are not updated to the mysql database, been trying several way but still the textbox value cant update the database, please help